As the pyridine derivatives having anti-ulcer activity, those disclosed in JPA S54(1979)-141783 (the corresponding U.S. Pat. No. 4,255,431), JPA S58(1983)-135881 (the correeesponding U.S. Pat. No. 4,472,409), JPA S61(1986)-50978 (the corresponding U.S. Pat. Nos. 4,628,098 and 4,689,333), etc. have been known.
However, a compound having a gastric mucous membrane protecting action stronger than that of those known compounds has been desired.
It is considered that gastrointestinal ulcer is induced by imbalance between aggressive factors, e.g. acid and pepsin, and defensive factors e.g. mucus secretion and mucosal blood flow. Therefore, a medication having an antisecretory action and an action of enhancing protection of the gastric mucosa has been desired.
The present inventors diligently studied with the purpose of preparing an anti-ulcer agent having excellent actions of inhibiting gastric acid secretion, of protecting gastric mucosa and of antagonizing. They found that a certain type of pyridine derivatives meet the said purpose, and they conducted further study to accomplish the present invention.